Bioinspired functional iron model complexes related to nitrogenase will be generated focusing on the activation of dinitrogen. Key reduced nitrogen intermediates in a Chatt-type cycle will be isolated and the physical and spectroscopic properties of these compounds examined. The basic physical properties of iron nitrides, nitrenes, diazenidos, hydrazido, amido and amine functionalities are desired. Initially a series of strong field ligands will be examined. Low valent iron complexes of these ligands are capable of activating dinitrogen, but the subsequent reactivity has not been explored. Of particular interest are iron (IV)-nitrides for their applicability to group transfer processes. A number of spectroscopic studies will be undertaken to detail the electronic structures of these unique intermediates. The mechanism of formation and decay of metal-dinitrogen intermediates will be studied via kinetic and spectroscopic methods. In the next phase, sulfur rich ligands will be examined and the possibility of the application to group transfer processes will be examined. Through the principles of nitrogen activation gained from these biomimetic complexes, greater understanding of the role of iron in nitrogenase will be gained. [unreadable] [unreadable]